Method and apparatus for folding of sheet materials

ABSTRACT

A method and apparatus for folding of sheet materials for forming a three-dimensional structure from a substantially two-dimensional sheet material includes a restraint assembly for restraining a work piece from movement in one direction, a low flange assembly movably mounted on the frame for biasing the work piece against the restraint assembly and effecting folding along the low-flange fold line, a high flange assembly movably mounted on the frame to effect folding along the high-flange fold line, and a control assembly for sequentially operating the low flange assembly and the high flange assembly. A method of using the method and apparatus for folding of sheet materials, and the structure created thereby, is also disclosed.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 60/911,905 filed Apr. 15, 2007, entitled METHOD AND APPARATUS FOR FOLDING OF SHEET MATERIALS, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates, in general, to tool systems for folding of sheet materials and methods for their use.

2. Description of Related Art

Bending two-dimensional (2D) sheet materials to form three-dimensional (3D) structures is known. Machinery and tooling for effecting bends in 2D sheet materials is also known. For example, U.S. Pat. No. 4,133,198 to Huda et al. discloses an apparatus for bending large area construction units. U.S. Pat. No. 4,230,058 to Iwaki et al. shows an apparatus that is configured to manufacture box-shaped structures from metal sheet. U.S. Pat. No. 5,105,640 to Moore discloses an apparatus for forming box-shaped sheet metal ducts from sheet material.

Known apparatuses generally have presses and/or clamping members provided to clamp the sheet material which may operate under similar levels of forces that are used to stamp, punch or otherwise work the sheet material into the desired shapes. The relatively high force levels mean that the presses and/or clamping members may present severe physical harm to an operator whom inadvertently catches a finger or limb within such componentry or between such componentry and the sheet material during the clamping or bending process.

A further disadvantage of known apparatuses is that they generally require the use of hardened steels and other metals that are highly machined with close tolerances in order to produce a 3D structure from a 2D sheet material. For example, known apparatuses which stamp or punch narrow peripheral flanges into a sheet material generally require hardened surfaces with close tolerances in order to accurately form the peripheral flanges with their desired dimensions.

Sheets of material with non-uniform, non-symmetrical flanges and bend lines present manufacturing complexities. A set of tools may be provided each of which accommodates bending of flanges of a particular scale, size, dimension, or configuration. With such conventional apparatus, bending along a bend line with a large flange portion often requires changing the tool or configuration than when bending flange portions on a smaller scale. The time and complexity increases as the number and variety of bend lines and flanges increase.

In light of the foregoing, it would be beneficial to have a folding system which overcomes the above and other disadvantages of known apparatuses for bending sheet materials.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention is directed to a folding tool system for forming a three-dimensional structure from a substantially two-dimensional sheet material which may include a predetermined low-flange fold line defining a low flange and a predetermined high-flange fold line defining a high flange. The system may include one or more of a frame including a restraint assembly for restraining a work piece from movement in one direction, a low flange assembly movably mounted on the frame for biasing the work piece against the restraint assembly and effecting folding along the low-flange fold line, the low flange assembly including a low-flange applicator for applying force against the low flange to effect low-flange folding, a high flange assembly movably mounted on the frame to effect folding along the high-flange fold line, the high flange assembly including a high-flange actuator for applying force against the high flange to effect high-flange folding, and a control assembly for sequentially operating the low flange assembly and the high flange assembly.

The restraint assembly may include a restraining block movable between a first position remote from the work piece and a second position for engaging the high flange of the work piece. The restraint assembly may further include a restraining plate movable between a retracted position and an extended position adjacent the low-flange fold line for restraining the work piece as the low flange assembly applies force against the low flange.

The low-flange applicator may include an applicator bar to apply substantially continuous force along a majority of the low flange to effect substantially uniform folding along the low-flange fold line. The applicator bar may be pivotally mounted to provide over-90° action to accommodate for spring-back of the low flange.

The high-flange actuator may include at least one arm pivoting about an axis substantially parallel to an adjacent the high-flange fold line. The arm may include a shoulder corresponding to a desired final shape of the work piece along the high-flange fold line.

The control system may include a controller for controlling the actuation sequence and dwell time of the low flange assembly and the high flange assembly. The control system may include a first pneumatic actuator controlling movement of the low flange assembly and a second pneumatic actuator controlling movement of the high flange assembly. The first pneumatic actuator may be an air bag dimensioned and configured to move the low flange assembly upward toward the restraining assembly. The second pneumatic actuator may be an pneumatic cylinder dimensioned and configured to move the high flange assembly to pivot along the high-flange fold line. The first pneumatic actuator operates in the range of approximately 50 psi and 150 psi. The second pneumatic actuator operates in the range of approximately 50 psi and 150 psi.

Another aspect of the present invention is directed to a folding tool system for forming a three-dimensional structure from a two-dimensional sheet material which may include a plurality of predetermined low-flange fold lines defining low flanges, a plurality of predetermined lateral high-flange fold lines defining lateral high flanges, and a plurality of predetermined end high-flange fold lines defining end high flanges. The system may include one or more of a frame including a restraint assembly for restraining a work piece from movement in one direction, a low flange assembly movably mounted on the frame for biasing the work piece against the restraint assembly and effecting folding along the low-flange fold lines, the low flange assembly including a plurality of low-flange applicators for applying force against the low flanges to effect low-flange folding along each of the low-flange fold lines, a high flange assembly movably mounted on the frame to effect folding along the high-flange fold lines, the high flange assembly including a plurality of lateral high-flange actuators for applying force against the lateral high flange to effect high-flange folding along each of the lateral high-flange fold lines, the high flange assembly further including a plurality of end high-flange actuators for applying force against the end high flanges to effect high flange folding along each of the end high-flange fold lines, and a control assembly for sequentially operating the low flange applicators, the lateral high-flange actuators, and the end high-flange actuators.

The restraint assembly may include a restraining block movable between a first position remote from the work piece and a second position for engaging the end high flanges. The restraint assembly may further include a restraining plate movable between a retracted position and an extended position adjacent the low-flange fold lines for restraining the work piece as the low flange assembly applies force against the low flanges.

The low-flange applicator may include a plurality of applicator bars to apply substantially continuous force along a corresponding one of the low flanges to effect substantially uniform folding along a corresponding one of the low-flange fold lines. The applicator bars may be pivotally mounted to provide over-90° action to accommodate for spring-back of the low flanges.

The high-flange actuators may include at least one arm pivoting about an axis substantially parallel to an adjacent and corresponding one of the high-flange fold lines. The arm may include a shoulder corresponding to a desired final shape of the work piece along the corresponding high-flange fold line.

The control system may include a controller for controlling the actuation sequence and dwell time of the low flange assembly, the lateral high-flange assembly, and the end high-flange assembly. The control system may include a first pneumatic actuator controlling movement of the low flange assembly and a second pneumatic actuator controlling movement of the high flange assembly. The first pneumatic actuator may be an air bag dimensioned and configured to move the low flange assembly upward toward the restraining assembly. The second pneumatic actuator may include a plurality of pneumatic cylinders dimensioned and configured to selectively move the lateral high-flange actuators and the end high-flange actuators. The first and second pneumatic actuators operate in the range of approximately 50 psi and 150 psi.

The system may be operated at force levels selected based on the properties of the work piece, to substantially eliminate the danger of damaging the work piece in the event of operator error. The system may be operated at force levels to substantially eliminate the danger of harming a human operator in the event of operator error. The system may be configured for folding along at least one of the fold lines may be achieved by using at least one of the restraint assemblies to contact the work piece at a location proximal to the fold line rather than substantially along the fold line. The system may be deployed in an assembly environment, rather than exclusively in a fabrication environment.

Another aspect of the present invention is directed to a method for forming a three-dimensional structure from an approximately two-dimensional sheet material, the sheet material including a predetermined low-flange fold line defining a low flange and a predetermined high-flange fold line defining a high flange. The method may include one or more of the steps of: restraining a work piece from movement in one direction; positioning a low flange assembly against the low flange to bias the work piece against the restraint assembly, the low flange assembly including a low-flange applicator contacting the low flange to effect folding along the low-flange fold line; and moving a high flange assembly against the high flange, the high flange assembly including a high-flange actuator contacting the high flange to effect folding along the high-flange fold line.

The restraining step may be accomplished by moving a restraining block between a first position remote from the work piece and a second position for engaging against one or more high flanges of the work piece. The restraining step may be accomplished by moving a restraining plate between a retracted position and an extended position adjacent one or more low-flange fold lines for restraining the work piece as the low flange assembly applies force against the low flanges.

The positioning step may be accomplished by positioning an applicator bar against one or more low flanges to apply substantially continuous force along a majority of one or more low flanges to effect substantially uniform folding along each corresponding low-flange fold line. The positioning step may be accomplished by moving the applicator bar beyond a targeted final bend angle, e.g. to an over-90° position, to accommodate for spring-back of the one or more low flanges.

The moving step may be accomplished by pivoting one or more arms pivoting about a corresponding axis substantially parallel to a corresponding high-flange fold line.

The positioning and moving steps may be accomplished by providing pneumatic pressure to control positioning of the low flange assembly and movement of the high flange assembly. The provided pneumatic pressure may be in the range of approximately 50 psi and 150 psi.

A three-dimensional structure may be formed by operation of the above-mentioned methods.

The method may be operated at force levels selected based on the properties of the work piece, to substantially eliminate the danger of damaging the work piece in the event of operator error. The method may be operated at force levels to substantially eliminate the danger of harming a human operator in the event of operator error.

Folding along at least one of the fold lines may be achieved by using at least one of the restraint assemblies to contact the work piece at a location proximal to the fold line rather than substantially along the fold line. The method may be deployed in an assembly environment, rather than exclusively in a fabrication environment.

The method and apparatus for folding of sheet materials of the present invention has other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric view of an exemplary apparatus for folding of sheet materials, and FIG. 1B is an end elevational schematic view of the apparatus of FIG. 1A.

FIG. 2A is an isometric view of a sheet of material that is configured for folding with the apparatus of FIG. 1, and FIG. 2B, FIG. 2C and FIG. 2D are enlarged isometric views of the sheet of material of FIG. 2A during progressive stages of folding.

FIG. 3A is an enlarged partial isometric view of the apparatus of FIG. 1 during an initial stage of folding the sheet of material of FIG. 2A, and FIG. 3B and FIG. 3C are partial elevational views of FIG. 3A.

FIG. 4A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 4B and FIG. 4C are partial elevational views of FIG. 4A.

FIG. 5A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 5B and FIG. 5C are partial elevational views of FIG. 5A.

FIG. 6A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 6B and FIG. 6C are partial elevational views of FIG. 6A.

FIG. 7A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 7B and FIG. 7C are partial elevational views of FIG. 7A.

FIG. 8A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 8B and FIG. 8C are partial elevational views of FIG. 8A.

FIG. 9A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 9B and FIG. 9C are partial elevational views of FIG. 9A.

FIG. 10A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 10B and FIG. 10C are partial elevational views of FIG. 10A.

FIG. 11A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 11B and FIG. 11C are partial elevational views of FIG. 11A.

FIG. 12A is an enlarged partial isometric view of the apparatus of FIG. 1 during another stage of folding the sheet of material of FIG. 2A, and FIG. 12B and FIG. 12C are partial elevational views of FIG. 12A.

FIG. 13 is an enlarged elevational view of a leveling device of the apparatus of FIG. 1.

FIG. 14 an enlarged elevational view of the leveling device of FIG. 14 in which the leveling device is in a leveling position.

FIG. 15 an enlarged elevational view of the leveling device of FIG. 14 in which the leveling device is in another leveling position.

FIG. 16A, FIG. 16B, FIG. 16C, FIG. 16D and FIG. 16E are schematic views of another restraint assembly that may be used with the apparatus of FIG. 1.

FIG. 17A is an enlarged partial isometric view of another apparatus similar to that shown in FIG. 1, while FIG. 17B, FIG. 17C, FIG. 17D and FIG. 17E are isometric views of the apparatus in successive stages of folding the sheet of material similar to that shown in FIG. 2A.

FIG. 18A is a schematic view of an apparatus similar to that shown in FIG. 1, while FIG. 18B, FIG. 18C, FIG. 18D, FIG. 18E, FIG. 18F, FIG. 18G and FIG. 18H are schematic views of the apparatus of FIG. 18A in successive stages of folding the sheet of material in a manner similar to that shown in FIG. 2A.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with several exemplary embodiments, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to FIGS. 1A and 1B, which illustrate an exemplary folding tool system generally designated by the numeral 30 that may be used to fold two-dimensional (2D) sheet materials into three-dimensional (3D) shapes. The folding tool system designed to be used with sheet materials having engineered fold lines which facilitate bending along predetermined fold lines.

The bending tool systems in accordance with the present invention are particularly suited for bending 2D sheet materials having engineered fold lines utilizing various fold geometries and configurations including, but not limited to, those disclosed by U.S. Pat. No. 6,481,259, U.S. Pat. No. 6,877,349, U.S. Pat. No. 7,152,449, U.S. Pat. No. 7,152,450, U.S. patent application Ser. No. 10/821,818 (now U.S. Patent Application Publication No. 2005/0005670 A1), and U.S. Pat. No. 7,032,426, U.S. patent application Ser. No. 10/931,615 (now U.S. Patent Application Publication No. 2005/0097937 A1), U.S. patent application Ser. No. 10/985,373 (now U.S. Patent Application Publication No. 2005/0061049 A1), U.S. patent application Ser. No. 11/357,934 (now U.S. Patent Application Publication No. 2006/0261139 A1), U.S. patent application Ser. No. 10/952,357 (now U.S. Patent Application Publication No. 2005/0064138 A1), U.S. patent application Ser. No. 11/384,216 (now U.S. Patent Application Publication No. 2006/0207212 A1), U.S. patent application Ser. No. 11/080,288 (now U.S. Pat. No. 7,350,390 B2), U.S. patent application Ser. No. 11/374,828 (now U.S. Patent Application Publication No. 2006/0213245 A1), U.S. patent application Ser. No. 11/180,398 (now U.S. Patent Application Publication No. 2006/0021413 A1, U.S. patent application Ser. No. 11/290,968 (now U.S. Patent Application publication No. 2006/0075798 A1, and U.S. patent application Ser. No. 11/411,440, the entire contents of which patents and patent applications are incorporated herein for all purposes by this reference.

The folding tool system of the present invention is designed to take advantage of various aspects of manufacturing with engineered fold lines. For example, accurate machine tool tolerances are relatively less critical because the locations of the bends necessary are engineered into the sheets of material. Accordingly, the folding tool system of the present invention can, but need not, take the form of a light-duty machine formed of mild steel which may be capable of millions of duty cycles due to relatively minimal wear and tear. Special metals, expensive and time-consuming machining, hardening and other heat treatments may be reduced or avoided because the need for precise machine tool tolerances is reduced: the tolerances are built into the sheet of material whereby a less expensive and lighter duty folding tool may be utilized to fold a 2D sheet of material into its final shape, or in some cases its intermediate shape. As such, the folding tool system may be constructed with milder steel, laser cut parts and other relatively inexpensive components such as including plastic, composite and other materials typically considered to be too soft to be built from metal forming equipment, as well as die cast and other relatively less precise componentry. Of course, the foregoing does not necessarily preclude heavy-duty construction using hardened steels. Rather, it allows enhanced flexibility depending on factors such as duty cycle, economy, weight, and the like.

In addition, some aspects of the folding tool system are similar to those disclosed in U.S. patent application Ser. No. 10/938,170 (now U.S. Pat. No. 7,296,455 B2), and U.S. Patent Application No. 60/840,810 (now U.S. patent application Ser. No. 11/846,134 and U.S. Patent Application Publication No. US 2008/0048366 A1), the entire contents of which patent applications are also incorporated herein for all purposes by this reference.

One will appreciate, however, that the folding tool system is also suited for bending other types of sheet materials about a fold line including, but not limited to, the above-mentioned engineered fold lines, predetermined fold lines defined by scoring and/or other suitable means, or intended bend lines in which the sheet materials do not have any physical structure extending along the bend line for promoting bending along the bend line.

Returning to FIG. 1A, folding tool system 30 is configured to fold a 2D sheet material blank into a 3D sheet material product. For the purposes of the following description, the sheet material will be generally designated by the numeral 32 regardless of its state of manufacture. In particular, whether with the sheet of material is in the flat as shown in FIG. 2A and FIG. 2B, in an intermediate state of manufacture as shown in FIG. 2C, or in a final state of manufacture as shown in FIG. 2D, the reference numeral 32 will be used. In fact, both the 2D and 3D states of the sheet material are illustrated in FIG. 1A.

In the illustrated embodiment, the sheet of material is provided with a plurality of fold lines 33, 35, 37 and 39 which dimensioned and arranged to facilitate folding into a 3D product having peripheral low flanges or narrow peripheral flanges 40, latching low flanges or narrow latching flanges 42, lateral high flanges or deep side walls 44, and end high flanges or deep end walls 46, as best seen in FIG. 2A. The illustrated 3D product is a household load center or primary distribution box, one that is in the form of an open box having self-latching side walls and a peripheral flange defining the primary opening of the box. One will appreciate that a number of other 3D products may be formed which include both low flanges and high flanges. For example, the 3D products may include, but are not limited to, electronic component chassis, automotive components, appliance components, transport components, construction components, RF shields, HVAC components, aerospace, aerospace components, and the like.

The terms “low” and “high”, “shallow” and “deep”, and “narrow” and “wide” are used in a relative sense. For example, what is low in one application may be high in another, or vice versa. Also, as between a “very low” and “low” pair of flanges, the former may be regarded as “low” and the latter as “high.” For the purposes of convenience, and without limiting the generality of the foregoing, the term “low flange” may be referred to herein a shallow or narrow flange, and the term “high flange” may be referred to herein as a deep or wide flange or side wall. Generally, low flanges require relatively more, and often significantly more, support to bend uniformly along a desired fold line as less material is present to distribute bending force. On the other hand, high flanges require relatively less, and often significantly less, support to bend uniformly along a desired bend line, as will be discussed in greater detail below. In part, the size of the flange determines the size of the “lever arm” and accordingly the force required for bending.

Returning to FIG. 1A, folding tool system 30 generally includes a frame 47 that supports a restraint assembly 49, a low flange assembly 51, and a high flange assembly 53. Unlike conventional hard tooling solutions, the folding tool system can be configured to fold 2D sheet materials of varying size to form 3D products of varying size. In the illustrated embodiment, the restraint assembly may be longitudinally repositioned in the direction of arrow “L” in order to accommodate distribution boxes of varying lengths, which lengths are indicated by numeral 54. One will also appreciate that the folding tool system such that the restraint assembly may be configured to lateral repositioning in directions laterally transverse and/or vertically perpendicular to arrow “L” in order to accommodate distribution boxes of varying widths and heights.

In the illustrated embodiment, the restraint assembly is located above the work piece. As shown in FIG. 3A the restraint assembly includes a restraining bar 56 that pivots down and abuts against each side wall to restrain upward motion of the work piece. Each restraining bar is configured to contact the side wall adjacent the low-flange peripheral fold line 33 to facilitate bending along the fold line

In the illustrated embodiment, the restraining bar extends continuously along a majority of the peripheral flange. One will appreciate, however, that the restraining bar need not be continuous but may instead be segmented. Preferably, the restraining bar contacts a sufficient portion of the peripheral flanges to facilitate substantially uniform bending along the corresponding fold line.

The restraint assembly also includes a restraining block 58 that pivots down and abuts against end high flange 46 and restrains upward motion of the work piece in a manner similar to the restraining bar discussed above. In the illustrated embodiment, the restraining block has a shape and dimensions that substantially conform with the end wall. One will appreciate that other configurations may be utilized such as restraining arms or other more localized restraints.

The primary purpose of the restraints is to limit upward motion. Since the sheet of material includes engineered fold lines, the fold lines will dictate where the sheet of material bends. As such, the restraining bar and the restraining blocks need only contact the side and end walls proximal the peripheral fold lines and not precisely along the fold lines. The precise locations of the restraining bar and block are relatively less critical. As relatively more precise tolerances are necessary, these components may also be constructed with milder steel, laser cut parts and other relatively inexpensive components such as including plastic, composite and other materials typically considered to be too soft to be built from metal forming equipment, as well as die cast and other relatively less precise componentry, as noted above.

The restraining bars and the restraining blocks are movable between upper retracted positions and lower deployed positions, the significance of which positions will become apparent below. Preferably, but not necessarily, double-acting pneumatic actuators 60, 61 are provided to control their respective movement, however, one will appreciate that other suitable actuators may be utilized such as single-acting pneumatic cylinders, a combination of single- and double-acting pneumatic cylinders, single- and/or double-acting hydraulic cylinders, electric motors, linear actuators and other suitable means.

The low flange assembly is mounted on the frame and is preferably configured to bend all narrow flanges at substantially the same time to minimize cycle time. In the illustrated embodiment, low flange assembly 51 is mounted on a pair of pneumatic air bags 63 serve to lift the low flange assembly upward relative to the main frame 47, as indicated by the arrow “U” in FIG. 1B. Platform 65 of the low flange assembly rises to bias sheet of material 32 against the retraining bar and blocks 56 and 58, and rises further to effect bending all of the narrow flanges substantially simultaneously. The sequence of bending a plurality of flanges of varying size may be modified depending on the application. In various embodiments, only one or a portion of the narrow flanges are bent substantially simultaneously and thereafter one or a portion of other flanges are bent. In various embodiments, all flanges of a similar size or in proximity to each other on the sheet are bent substantially simultaneously.

With reference to FIG. 3A, the low flange assembly further includes a number of force applicators 67, 68, 70 which abut against and apply force to “wipe” the corresponding narrow flanges 40, 42 upwardly past the lower surfaces of the restraining bars and blocks 56, 58. As the applicators wipe the narrow flanges past the restraining bars and blocks, the applicators effect bending along the corresponding fold line and actually form the narrow flanges. In the illustrated embodiment, the actuators are in the form of cylindrical bars mounted on platform 65, which bars extend substantially the length of the narrow flanges and thus apply a substantially continuous force against the narrow flanges. One will appreciate that the bars need not be continuous but instead may be segmented, provided that the bars contact a majority of the length of the narrow flanges in order to promote substantially uniform bending along the corresponding fold line.

Also, the force applicators may be provided with a contact roller that is free to roll along the surface of the narrow flange during bending. Such a contact roller may prevent sliding contact of the applicator bar along the narrow flange and thus minimize scratching, wear or other damage to the work piece.

The force applicators may be provided with a cam actuator 72 such that an inward force may be applied inwardly to bend the narrow flanges over 90° as the assembly reaches the end of its upward stroke, as shown in FIG. 6B and FIG. 6C. Such a cam actuator may thus accommodate for spring-back in the narrow flange in an otherwise conventional manner.

In the illustrated embodiment, each applicator bar is dedicated to a single corresponding narrow flange. One will appreciate, however, that a single applicator bar may be utilized to fold a plurality of narrow flanges and, conversely, a plurality of applicator bars may be utilized to fold a single narrow flange.

The dimensions and configuration of the force applicators will dictate the particular angle bend imparted on the work piece. For example, in the illustrated embodiment, low flange applicators 67, 68, 70 are configured to impart a desired bend angle (e.g. approximately 90°), however, the actuators may be adjustable such that the bend angle may be adjusted by adjusting the throw of the applicators. Also, the bend angle may be adjusted to accommodate for spring back to achieve a desired final bend angle.

Turning now to the high flange assembly, it is also movably mounted on the frame and is configured to effect folding along the high-flange fold lines. In the illustrated embodiment, high flange assembly 53 including a plurality of lateral high-flange actuators 74, 75 which are configured to apply force against corresponding lateral and end high flanges 44, 46 to effect high-flange folding along the corresponding lateral high-flange fold lines. In the illustrated embodiment, the high-flange actuators are mounted on platform 65 and thus rise along with the low flange assembly, however, one will appreciate that the high-flange actuators may be otherwise movably mounted on frame 47.

Each high-flange actuator is provided with a double-acting pneumatic cylinder 77. As is the case with the retraining bar and block actuators discussed above, other suitable actuation means may be utilized instead of, or in addition to double-acting pneumatic cylinders. Also, one will appreciate that one or more cylinders may be provided for each actuator and, conversely, a cylinder may be provided for one or more actuators.

In the illustrated embodiment, the high-flange actuators include at least one arm 79 that pivots about an axis substantially parallel to a corresponding high-flange fold line. Preferably, the arm pivots directly below a bottom 81 of the work piece and includes a shoulder 82 which corresponds to a desired final shape of the work piece. Such configuration forms a cradle as the arms are pivoted upwardly, which cradle provides a self-centering effect on the work piece and also allows the deep flanges to be bent with little or no restraint from the restraining assembly. In particular, the light duty folding of the deep flanges, coupled with gravity and/or frictional forces allow the deep flanges to be bent with the work piece merely resting on and between the high-flange actuators.

Turning now to the operation of the above-mentioned pneumatic actuators, may be controlled by suitable means to control the pressure and dwell time of each actuator, as well as the actuation sequence of the actuators. For example, a programmable logic controller 84 having a multi-channel valve assembly may be provided to control the actuators in any desired combination, duration, and/or sequence. The controller may be configured with a manual override to activate any one or more actuators as desired, and/or with appropriate safety and/or off switches. One will appreciate that other suitable controllers may be utilized.

The pneumatic cylinders, or other actuation means, may be adjusted such that the force applied to the work piece is sufficient to bend the work piece along the engineered fold lines, while reducing or eliminating the risk of injury to the operator in the event that the operator inadvertently pinches a finger or limb. Similarly, the actuation means may be adjusted such that the tool system uses forces that are sufficiently low that there is less danger of damaging the work piece in the event of misalignment or other operator error. In various embodiments, the pneumatics are configured to operate in the range of approximately 10 psi to 200 psi. In various embodiments, the pneumatics operate in the range of approximately 50 psi to 150 psi. One will appreciate, however, that the operating pressures will depend on the product gauge of the material, the material strength, and/or other material characteristics including, but not limited to the usual commercial range for pneumatic equipment. For example, hydraulics or other higher force means may be appropriate for bending thick-gauge materials and/or with higher strength materials. While hydraulics and other higher force means may be utilized, it is preferable that pneumatics be used as pneumatics may be less messy and environmentally cleaner in use than hydraulics.

An exemplary method of using folding tool system 30, and an exemplary product resulting from use of the method, will now be described. Although the following describes with particular detail the process of folding one corner of the work piece, one will appreciate that all four corners may be similarly and simultaneously processed. With reference to FIG. 3A, work piece 32 is placed into the appropriate location while the restraining bar and block 56, 58 are in their retracted positions. As can be seen in FIG. 3B and FIG. 3C, the work piece is placed such that it is resting on applicator bars 67, 68, 70. In various embodiments, the cam actuators 72 are configured such that upper protrusions 86 locate the work piece within the tool system.

Next, the restraining bar and block 56, 58 swing down into their deployed positions as shown in FIG. 4A, and more particularly, as shown by the arrows in FIG. 4B and FIG. 4C. The restraining bar is positioned proximal the lateral peripheral low-flange fold line 33 while the restraining block is positioned adjacent the fold line 35. As such, the restraint assembly is now in place to restrain upward motion of the work piece.

As shown in FIGS. 5A, B and C, and in FIGS. 6A, B and C, the low flange assembly 51 is moved upwardly such that low flange applicators 67, 68, 70 wipe the corresponding narrow flanges upwardly above lower edges of the restraining bar and block 56, 58. In various embodiments, the targeted bend angle is approximately 90°. As the low flange assembly approaches the extent of its upward stroke, actuators 72 pivot and bias the narrow flanges inwardly past 90° to accommodate for spring back. The amount of such “overbending” depends in part on the characteristics of the material and bending process.

With reference to FIGS. 7A, B and C, restraining bar 56 swings toward its retracted position while the restraining block 58 remains in its downward deployed position. This allows restraint of the work piece while bending commences by the lateral high-flange actuators 74, as indicated by the arrow in FIG. 8B

Next, the lateral high-flange actuators complete 74 their stroke and bend lateral high flange or side wall 44 into its final position, as indicated by the arrow in FIG. 9B. As can be seen in FIG. 9B, restraining bar 56 is configured for double duty in that in its upper retracted position, the restraining also abuts against narrow flange 40 and thus serves to restrain upward motion of work piece 32. Such restraint is beneficial in holding the work piece in place as restraining block retracts upwardly (FIG. 10C), and as the end high-flange actuators 75 commence and progress through their stroke (FIG. 11C).

As shown in FIG. 2A, the work piece is provided with a latch assembly 88 of the type described in U.S. patent application Ser. No. 11/386,463 (now U.S. Patent Application Publication No. 2006/0277965 A1), the entire contents of which application is incorporated herein for all purposes by this reference. One will appreciate that additional force may be required to engage the latch assembly during bending. In which case, the high-flange end actuators 75 may be configured to provide more force than the other actuators. Also, the double-duty of the restraining bar 56 in its upper retracted position (FIG. 10B) serves to keep the work piece in position as the high-flange end actuators 75 pivot upwardly as shown in FIG. 10C. The restraining bar may abut against the lateral narrow flanges 40 during the entire stroke of the high-flange end actuator. However, and as noted above, due to the low duty bending afforded by engineered fold lines, it is may not be necessary to restrain the work piece during the entire stroke of the end actuators, in which case, the low flange assembly 51 may lower, as indicated by the arrow in FIG. 12B, while the end actuator completes its stroke as indicated by the arrow in FIG. 12C.

Turning to FIG. 13, the folding tool system may include a leveling device 89 in the form of an off-center cam lever provided on the base of frame 47. One or more leveling devices may be provided on the frame. For example, a leveling device may be provided at each corner of the folding tool system's footprint. Preferably, the frame includes at least three leveling devices to allow, and more preferably, one at each corner of the frame.

In the illustrated embodiment, the leveling device includes a body 91 and an adjustment lever 93. The body is pivotally mounted to frame 47 by a pivot assembly 95. In the illustrated embodiment, the pivot assembly includes a through bore and is pivotally mounted to the frame by a fastener such as a bolt, carriage screw, or other suitable means. Two or more pivot assemblies may be provided to vary the degree of adjustability afforded by the leveling device. For example, two or more bores may be provided at varying distance from the center of body 91. The further the bore is located from the center of the body, the greater the vertical adjustment may be realized.

As shown in FIG. 14, pivotally mounting leveling device 89 to frame 47 through one bore affords a certain degree of adjustability as the leveling device is pivoted approximately 75° as compared to its original position shown in phantom. Mounting the device to the other bore located further from the center of body 91 affords a greater degree of adjustability as the leveling device is pivoted approximately 75°, as shown in FIG. 15. One will appreciate that the pivot range of the leveling device may vary.

In the illustrated embodiment, body 91 is substantially circular; however, one will appreciate that other shapes may be utilized. For example, the body may have a nautilus-like profile in which the portion which contacts the ground or floor is located substantially directly below the pivot assembly in which case, the device is effectively self-locking, that is, does not have any significant propensity to rotate from its desired position.

The exemplary folding tool system described herein may provide a simpler and safer method of defining 3D objects from 2D sheet materials, than known devices. Additionally, the tool system may be used in the assembly environment instead of, or in addition to, the fabrication environment as it takes advantage of engineered fold lines and thus may reduce the necessity of press brakes, progressive dies and other heavy machinery. The folding tool system may also be readily located in an assembly line after or between various fabrication stations on which a profiling, punching, laser cutting or other operation takes place. Furthermore, the folding tool system may also be located in an assembly line before or after various finishing stations.

Also, the folding tool system allows 2D sheet material parts to be transported directly to the assembly space, and thus allows the product to the shipped in the flat through much of the manufacturing and assembly process as possible. Various methods can be utilized to feed the work piece to the folding tool system including either manual labor, or automated machinery, or a combination thereof.

In another exemplary embodiment of the present invention, restraint assembly 49 a is similar to restraint assembly 49 described above but includes a wipe bar 96 as shown in FIG. 16A. The configuration of restraint assembly 49 a allows for forming an outwardly extending peripheral flange, which results in an S-shaped or Z-shaped side wall. Also, the configuration of restraint assembly allows for a single actuator to fold both a peripheral low flange, and a lateral high flange. For example, the lateral high flange applicator may be utilized to fold both the peripheral low flange and the lateral high flange as will become evident below. One will appreciate that a single actuator may similarly be utilized to form both a peripheral low flange and an end high flange.

Like reference numerals have been used to describe like components of restraint assembly 49 a and restraint assembly 49. In this embodiment, the restraint assembly includes a restraining bar 56 a that is configured for pivotal movement in a manner similar to that described above. In this embodiment, wipe bar 96 is mounted on a pivoting restraining bar mount 98 as shown in FIG. 16A. As the lateral high flange actuator (not shown) begins to fold lateral high flange 44 a in a manner similar to that described above, peripheral low flange 40 a moves toward wipe bar 96, as shown in FIG. 16B, and contacts the wipe bar to cause folding of the peripheral low flange about the peripheral fold line, as shown in FIG. 16C. Preferably, restraining bar mount 98 is shaped to accommodate the folded low flange 40 a as it continues to move inward as folding of high flange 44 a is completed, as shown in FIG. 16D. Once folding is completed, the restraining bar mount 98 pivots upwardly about pivot 100 thereby swinging both restraining bar 56 a and wipe bar 96 out of the way, as shown in FIG. 16E, thereby allowing access for ready removal of the folded sheet of material.

In another exemplary embodiment of the present invention, folding tool system 30 b is similar to high-flange assembly 30 described above but includes modified low-flange and high-flange actuators, as shown in FIG. 17A. In this embodiment, the relative positioning of latch flange 42 b and lateral flange 44 b are controlled by single action, that is, by movement of the lateral high flange actuator 74 b. In this embodiment, low flange applicators 67 b, 68 b are similar to those described above. Applicators 67 b, 68 b abut against and apply force to “wipe” the corresponding narrow flanges 40 b upwardly in a manner similar to that described above. Latch flange applicator 70 b, however, does not cam inwardly and outwardly in the manner of applicator 70 described above. Instead, latch flange applicator 70 b holds latching flange 42 b in a substantially right angle position, even as high flange actuator 74 b begins to fold lateral high flange 44 b about its corresponding fold line, as shown in FIG. 17B.

In the illustrated embodiment, latch flange applicator 70 b is in the form of a block, however, other suitable shapes and configurations may be utilized. Preferably, the latch flange applicator has a chamfered top to facilitate “wiping” the latching flange upwardly. Also, latch flange applicator 70 b may be provided with an latch flange adjuster 102 to fine tune the position of the latching flange.

High flange actuator 74 b is configured to contact and fold lateral high flange 44 b in a manner similar to that described above. In this embodiment, the high flange actuator also includes a tuned swing plate 74 b′. The tuned swing plate is positioned just beyond the end of the high flange to contact latching flange 42 b, as shown in FIG. 17C, and properly position the latching flange as the end flange 46 b is folded upwardly, as shown in FIG. 17D. Preferably, the contact surface of swing plate 74 b′ is offset approximately, or slightly greater than the material thickness of sheet 32 b. Such configuration of the swing plate will bias the outside surface of latching flange 42 b slightly inside of the inside surface of lateral flange 44 b to provide proper clearance for folding end flange 46, while properly aligning the latching flange for proper engagement of latching assembly 88 b as the folding operation is completed, as shown in FIG. 17E.

The swing plate may include a ramped or chamfered surface 103, or be otherwise configured to facilitate the latching flange sliding across the swing plate and inward of the lateral flange. One will also appreciate that suitable adjustment means may be provided to fine tune the position of the swing plate with respect to the remainder of lateral high flange actuator.

In another exemplary embodiment of the present invention, folding tool system 30 c is similar to folding tool system 30 described above and is configured for a method of “overbending” to accommodate for material spring-back without a rocker assembly (e.g., cam actuator 72), as is shown in FIGS. 18A-H. Like reference numerals have been used to describe like components of the folding tool system. Folding tool system 30 c includes a platform 65 c with a riser 106 and a bend applicator 108 fixedly mounted with respect to the riser and positioned on the platform spaced from the riser. The bend applicator is configured to engage the sheet of material and apply an opposing force to the underside of the sheet.

In the illustrated embodiment, the bend applicator is a rod, however, one will appreciate that in various embodiments the bend applicator may have other configurations which include a chamfered, ramped or curved surface to promote sliding of the material along a bend line into the space between the bend applicator and the inclined portion of the platform. In the illustrated embodiment, the riser is a stepped riser block, however, one will appreciate that in various embodiments the riser may have other configuration which include a chamfered, ramped or other geometry to provide suitable clearance for elastic bending as described below.

In operation, the sheet of material 32 c is placed on the platform and bend applicator while they remain substantially stationary as shown in FIG. 18B, and the platform and bend applicator is moved upwardly against a restrainer as discussed below. In various embodiments, the tool system may be configured such that the sheet moves with the platform and bend applicator, while in other embodiments, the tool system may be configured such that the sheet moves relative to the platform and/or bend applicator. By designing the system for movement of the sheet rather than the platform parts, the system may achieve greater flexibility and simplicity of moving parts.

As shown in FIGS. 18C and 18D, an end of the sheet of material engages bend applicator 108 as the bend applicator moves toward the sheet and “wipes” along the undersurface of the sheet. As such, bend applicator 108 imparts bending along a bend line 110 while a restrainer 111 restrains the sheet from upward movement. In various embodiments, the sheet of material includes bend-inducing structures to facilitate bending at the intended bending location as described above (e.g. bend line 110).

After engaging the bend applicator, the sheet of material is restrained downwardly until a portion of the sheet engages riser 106, as shown in FIG. 18D. At this time, the end of the sheet material is provided with a desired angle α, which provides a substantially 90° flange in the exemplary embodiment.

As shown in FIG. 18E, the combination of the bend applicator and riser provides a geometry which causes the sheet of material to bend beyond the desired angle α to an over-bend angle β, which is slightly over 90° (e.g., approximately 89° to 85°, or more) in the illustrated embodiment. In part, the bend angle is determined by the direction of application force on the sheet and angle of incidence of an inclined portion of the sheet as riser 106 moves above the bottom edge of restrainer 111. As can be seen in FIG. 18 e, a flange 32 c′ of the sheet of material is folded such that it extends in a direction coincident with the line of application on the sheet. Along bend line 110, however, the sheet of material is forced into a void between the riser 106 and bend applicator 108. In this fully engaged position, a portion of the sheet of material is pushed toward platform 65 c such that the sheet of material temporarily bends along two bend lines, bend line 110 and bend line 110′. Whereas bending along bend line 110 is effected by bend applicator 108, bend line 110′ is determined by an inflection point 112 formed by an edge of the riser.

The riser 106, and in particular the edge thereof, is configured and dimensioned to minimally bend the sheet such that only elastic deformation of the sheet of material occurs along bend line 110′. In contrast, bend applicator 108 is dimensioned and configured to effect significant bending which causes the sheet of material to plastically deform along bend line 110. Elastic bending means that the sheet of material is bent such that the bending is within the elastic region of the material or is less than the yield point. The bending is not severe enough to plastically or permanently deform the material.

As shown in FIG. 18F, platform 65 c and sheet of material 32 c are lowered during which time, the sheet of material is allowed to “spring back” such that material has substantially a 90° bend along bend line 110 and is substantially unbent along bend line 110′. In particular, the sheet will “spring back” to a substantially planar form along bend line 110′ as shown in FIG. 18F. Further, the sheet of material will also experience some spring back along bend line 110. This is due to the material characteristics of the sheet which determine that part of the bending is within the elastic region.

Next, platform 65 c and bend applicator 108 are further lowered such that restrainer 111 disengages the sheet of material, as shown in FIG. 18G, and the sheet of material is removed altogether from the platform, as shown in FIG. 18H. As shown in FIG. 18H, the sheet of material in the final state has a 900 bend along bend line 110 and substantially no bending in the region of inflection point 112.

Although apparatus 30 c is designed to produce a 90° bend after spring back, the apparatus may be modified to produce any number and type of bends and bend angles. For example, the platform may include inflection points of varying size, number, shape, and location which define a plurality of inclined portions. The slope of one or more of the inclined portions may be configured to impart bending beyond the yield point of the material to cause some plastic deformation. The inflection point angle and length of the inclined portion may also be modified to adjust the final bend angle of the sheet of material. The platform may also include a variety of applicator configurations including, but not limited to, a plurality of applicators of varying shapes and sizes. The use of a plurality of applicators and other modifications of the platform working surface allows the system to perform several processes in a substantially singular step as the sheet is forced against the platform. The platform may be modified in many other ways depending on the application to accommodate and utilize the deformation properties of the sheet of material.

For convenience in explanation and accurate definition in the appended claims, the terms “up” or “upper”, “down” or “lower”, “inside” and “outside”, “lateral” and “end” are used to describe features of the present inventions with reference to the positions of such features as displayed in the figures.

In many respects various modified features of the various figures resemble those of preceding features and the same reference numerals followed by subscripts “a” and “b” designate corresponding parts.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. A folding tool system for forming a three-dimensional structure from a substantially two-dimensional sheet material which includes a predetermined low-flange fold line defining a low flange and a predetermined high-flange fold line defining a high flange, said system comprising: a frame including a restraint assembly for restraining a work piece from movement in one direction; a low flange assembly movably mounted on the frame for biasing the work piece against the restraint assembly and effecting folding along the low-flange fold line, the low flange assembly including a low-flange applicator for applying force against the low flange to effect low-flange folding; a high flange assembly movably mounted on the frame to effect folding along the high-flange fold line, the high flange assembly including a high-flange actuator for applying force against the high flange to effect high-flange folding; and a control assembly for sequentially operating the low flange assembly and the high flange assembly.
 2. A system according to claim 1, wherein the restraint assembly includes a restraining block movable between a first position remote from the work piece and a second position for engaging the high flange of the work piece.
 3. A system according to claim 2, wherein the restraint assembly further includes a restraining plate movable between a retracted position and an extended position adjacent the low-flange fold line for restraining the work piece as the low flange assembly applies force against the low flange.
 4. A system according to claim 1, wherein the low-flange applicator includes an applicator bar to apply substantially continuous force along a majority of the low flange to effect substantially uniform folding along the low-flange fold line.
 5. A system according to claim 4, wherein the applicator bar is pivotally mounted to provide over-90° action to accommodate for spring-back of the low flange.
 6. A system according to claim 1, wherein the high-flange actuator includes at least one arm pivoting about an axis substantially parallel to an adjacent the high-flange fold line.
 7. A system according to claim 6, wherein the arm includes a shoulder corresponding to a desired final shape of the work piece along the high-flange fold line.
 8. A system according to claim 1, wherein the control system comprises a controller for controlling the actuation sequence and dwell time of the low flange assembly and the high flange assembly.
 9. A system according to claim 8, wherein the control system includes a first pneumatic actuator controlling movement of the low flange assembly and a second pneumatic actuator controlling movement of the high flange assembly.
 10. A system according to claim 9, wherein the first pneumatic actuator is an air bag dimensioned and configured to move the low flange assembly upward toward the restraining assembly.
 11. A system according to claim 9, wherein the second pneumatic actuator is an pneumatic cylinder dimensioned and configured to move the high flange assembly to pivot along the high-flange fold line.
 12. A system according to claim 9, wherein the first pneumatic actuator operates in the range of approximately 50 psi and 150 psi.
 13. A system according to claim 9, wherein the second pneumatic actuator operates in the range of approximately 50 psi and 150 psi.
 14. A folding tool system for forming a three-dimensional structure from a two-dimensional sheet material which includes a plurality of predetermined low-flange fold lines defining low flanges, a plurality of predetermined lateral high-flange fold lines defining lateral high flanges, and a plurality of predetermined end high-flange fold lines defining end high flanges, said system comprising: a frame including a restraint assembly for restraining a work piece from movement in one direction; a low flange assembly movably mounted on the frame for biasing the work piece against the restraint assembly and effecting folding along the low-flange fold lines, the low flange assembly including a plurality of low-flange applicators for applying force against the low flanges to effect low-flange folding along each of the low-flange fold lines; a high flange assembly movably mounted on the frame to effect folding along the high-flange fold lines, the high flange assembly including a plurality of lateral high-flange actuators for applying force against the lateral high flange to effect high-flange folding along each of the lateral high-flange fold lines, the high flange assembly further including a plurality of end high-flange actuators for applying force against the end high flanges to effect high flange folding along each of the end high-flange fold lines; and a control assembly for sequentially operating the low flange applicators, the lateral high-flange actuators, and the end high-flange actuators.
 15. A system according to claim 14, wherein the restraint assembly includes a restraining block movable between a first position remote from the work piece and a second position for engaging the end high flanges.
 16. A system according to claim 15, wherein the restraint assembly further includes a restraining plate movable between a retracted position and an extended position adjacent the low-flange fold lines for restraining the work piece as the low flange assembly applies force against the low flanges.
 17. A system according to claim 14, wherein the low-flange applicator includes a plurality of applicator bars to apply substantially continuous force along a corresponding one of the low flanges to effect substantially uniform folding along a corresponding one of the low-flange fold lines.
 18. A system according to claim 17, wherein the applicator bars are pivotally mounted to provide over-90° action to accommodate for spring-back of the low flanges.
 19. A system according to claim 14, wherein the high-flange actuators include at least one arm pivoting about an axis substantially parallel to an adjacent and corresponding one of the high-flange fold lines.
 20. A system according to claim 19, wherein the arm includes a shoulder corresponding to a desired final shape of the work piece along the corresponding high-flange fold line.
 21. A system according to claim 14, wherein the control system comprises a controller for controlling the actuation sequence and dwell time of the low flange assembly, the lateral high-flange assembly, and the end high-flange assembly.
 22. A system according to claim 21, wherein the control system includes a first pneumatic actuator controlling movement of the low flange assembly and a second pneumatic actuator controlling movement of the high flange assembly.
 23. A system according to claim 22, wherein the first pneumatic actuator is an air bag dimensioned and configured to move the low flange assembly upward toward the restraining assembly.
 24. A system according to claim 22, wherein the second pneumatic actuator includes a plurality of pneumatic cylinders dimensioned and configured to selectively move the lateral high-flange actuators and the end high-flange actuators.
 25. A system according to claim 22, wherein the first and second pneumatic actuators operate in the range of approximately 50 psi and 150 psi.
 26. The system according to claim 1 configured to be operated at force levels selected based on the properties of the work piece, to substantially eliminate the danger of damaging the work piece in the event of operator error.
 27. The system according to claim 1 configured to be operated at force levels to substantially eliminate the danger of harming a human operator in the event of operator error.
 28. The system according to claim 1 configured for folding along at least one of the fold lines is achieved by using at least one of the restraint assemblies to contact the work piece at a location proximal to the fold line rather than substantially along the fold line.
 29. The system according to claim 1 configured to be deployed in an assembly environment, rather than exclusively in a fabrication environment.
 30. A method for forming a three-dimensional structure from an approximately two-dimensional sheet material, the sheet material including a predetermined low-flange fold line defining a low flange and a predetermined high-flange fold line defining a high flange, said method comprising the steps of: restraining a work piece from movement in one direction; positioning a low flange assembly against the low flange to bias the work piece against the restraint assembly, the low flange assembly including a low-flange applicator contacting the low flange to effect folding along the low-flange fold line; and moving a high flange assembly against the high flange, the high flange assembly including a high-flange actuator contacting the high flange to effect folding along the high-flange fold line.
 31. A method according to claim 30, wherein the restraining step is accomplished by moving a restraining block between a first position remote from the work piece and a second position for engaging against one or more high flanges of the work piece.
 32. A method according to claim 31, wherein the restraining step is accomplished by moving a restraining plate between a retracted position and an extended position adjacent one or more low-flange fold lines for restraining the work piece as the low flange assembly applies force against the low flanges.
 33. A method according to claim 31, wherein the positioning step is accomplished by positioning an applicator bar against one or more low flanges to apply substantially continuous force along a majority of one or more low flanges to effect substantially uniform folding along each corresponding low-flange fold line.
 34. A method according to claim 33, wherein positioning step is accomplished by moving the applicator bar to an over-90° position to accommodate for spring-back of the one or more low flanges.
 35. A method according to claim 31, wherein the moving step is accomplished by pivoting one or more arms pivoting about a corresponding axis substantially parallel to a corresponding high-flange fold line.
 36. A method according to claim 31, wherein the positioning and moving steps are accomplished by providing pneumatic pressure to control positioning of the low flange assembly and movement of the high flange assembly.
 37. A method according to claim 36, wherein the provided pneumatic pressure is in the range of approximately 50 psi and 150 psi.
 38. A three-dimensional structure formed by operation of the method of claim
 30. 39. The method according to claim 30 operated at force levels selected based on the properties of the work piece, to substantially eliminate the danger of damaging the work piece in the event of operator error.
 40. The method according to claim 30 operated at force levels to substantially eliminate the danger of harming a human operator in the event of operator error.
 41. The method according to claim 30, wherein folding along at least one of the fold lines is achieved by using at least one of the restraint assemblies to contact the work piece at a location proximal to the fold line rather than substantially along the fold line.
 42. The method according to claim 30 deployed in an assembly environment, rather than exclusively in a fabrication environment. 